The present invention relates to imaging systems for a printing press.
In the past, printing presses have utilized plate cylinders in conjunction with blanket cylinders in order to form printed images on a paper web as the web passes the blanket cylinders. Such plate cylinders have utilized plates containing the image for printing, and the plates have been secured to the outer surface of the plate cylinders for use. The plate cylinders have passed an ink image onto the blanket cylinders which in turn print the images on the web.
The formation of the plates has been time consuming, and it has been difficult to secure the plates onto the plate cylinders through the use of some locking mechanism. It has been particularly tedious and time consuming to maintain registration between a plurality of associated plate and blanket cylinders, thus rendering the printing press more inefficient.
More recently, it has been proposed to form the printing image directly upon a print cylinder, rather than forming separate plates. The print cylinders are then associated with the blanket cylinders, and the printing image is transferred from the print cylinders to the blanket cylinders for printing the image onto the web. However, many difficulties are still found to exist in such direct-to-press imaging systems, and much improvement is needed in such presses to obtain a satisfactory result. For example, such presses have required extensive cleaning of the print cylinders after their use, and have also required surface preparation of the print cylinders prior to placement of the image on the outer surface of the print cylinders.